libuv_readlink_function

Adds wrapper function in C in jl_uv.c as well as the necessary
documentations and tests.

base/exports.jl

@@ -1280,6 +1280,7 @@ export
  mv,
  operm,
  pwd,
+ readlink,
  rm,
  stat,
  symlink,

base/fs.jl

@@ -23,6 +23,7 @@ export File,
  rename,
  sendfile,
  symlink,
+ readlink,
  chmod,
  futime,
  JL_O_WRONLY,
@@ -163,6 +164,18 @@ end
 @windowsxp_only symlink(p::AbstractString, np::AbstractString) =
  error("WindowsXP does not support soft symlinks")
 
+function readlink(path::AbstractString)
+ req = Libc.malloc(_sizeof_uv_fs)
+ ret = ccall(:uv_fs_readlink, Int32,
+ (Ptr{Void}, Ptr{Void}, Ptr{UInt8}, Ptr{Void}),
+ eventloop(), req, path, C_NULL)
+ uv_error("readlink", ret)
+ tgt = bytestring(ccall(:jl_uv_fs_t_ptr, Ptr{Cchar}, (Ptr{Void}, ), req))
+ ccall(:uv_fs_req_cleanup, Void, (Ptr{Void}, ), req)
+ Libc.free(req)
+ tgt
+end
+
 function chmod(p::AbstractString, mode::Integer)
  err = ccall(:jl_fs_chmod, Int32, (Ptr{UInt8}, Cint), p, mode)
  uv_error("chmod",err)

doc/helpdb.jl

@@ -5021,6 +5021,12 @@ Millisecond(v)
 
 "),
 
+("Base","readlink","readlink(path) -> AbstractString
+
+ Returns the value of a symbolic link \"path\".
+
+"),
+
 ("Base","chmod","chmod(path, mode)
 
  Change the permissions mode of \"path\" to \"mode\". Only integer

doc/stdlib/file.rst

@@ -40,6 +40,10 @@
  This function raises an error under operating systems that do not support
  soft symbolic links, such as Windows XP.
 
+.. function:: readlink(path) -> AbstractString
+
+ Returns the value of a symbolic link ``path``.
+
 .. function:: chmod(path, mode)
 
  Change the permissions mode of ``path`` to ``mode``. Only integer ``mode``\ s

test/file.jl

@@ -1,24 +1,40 @@
 #############################################
 # Create some temporary files & directories #
 #############################################
-
 starttime = time()
+pwd_ = pwd()
 dir = mktempdir()
 file = joinpath(dir, "afile.txt")
 close(open(file,"w")) # like touch, but lets the operating system update the timestamp for greater precision on some platforms (windows)
 
-@unix_only begin
- link = joinpath(dir, "afilelink.txt")
- symlink(file, link)
-end
-
 subdir = joinpath(dir, "adir")
 mkdir(subdir)
+subdir2 = joinpath(dir, "adir2")
+mkdir(subdir2)
+
 @non_windowsxp_only begin
  dirlink = joinpath(dir, "dirlink")
  symlink(subdir, dirlink)
+ # relative link
+ cd(subdir)
+ relsubdirlink = joinpath(subdir, "rel_subdirlink")
+ reldir = joinpath("..", "adir2")
+ symlink(reldir, relsubdirlink)
+ cd(pwd_)
 end
 
+@unix_only begin
+ link = joinpath(dir, "afilelink.txt")
+ symlink(file, link)
+ # relative link
+ cd(subdir)
+ rellink = joinpath(subdir, "rel_afilelink.txt")
+ relfile = joinpath("..", "afile.txt")
+ symlink(relfile, rellink)
+ cd(pwd_)
+end
+
+
 #######################################################################
 # This section tests some of the features of the stat-based file info #
 #######################################################################
@@ -50,9 +66,12 @@ end
 
 # test links
 @unix_only @test islink(link) == true
+@unix_only @test readlink(link) == file
+
 @non_windowsxp_only begin
  @test islink(dirlink) == true
  @test isdir(dirlink) == true
+ @test readlink(dirlink) == subdir * @windows? "\\" : ""
 end
 
 # rename file
@@ -412,11 +431,17 @@ test_LibcFILE(Libc.FILE(f,Libc.modestr(true,false)))
 ############
 # Clean up #
 ############
-@unix_only rm(link)
-@non_windowsxp_only rm(dirlink)
-
+@unix_only begin
+ rm(link)
+ rm(rellink)
+end
+@non_windowsxp_only begin
+ rm(dirlink)
+ rm(relsubdirlink)
+end
 rm(file)
 rm(subdir)
+rm(subdir2)
 rm(dir)
 
 # The following fail on Windows with "stat: operation not permitted (EPERM)"